1882.] | ON THE MOLLUSCAN FAUNA OF MADAGASCAR. 375 
Although this species is so closely connected with C. aspersus 
and C. vermiculatus, I think it deserves to be separated from them 
at present. Dr. Cabanis, when answering my questions respecting 
this species, says:—‘‘ Your Orypturus is not very different from 
C. adspersus, Licht. (which I consider identical with C. vermiculatus, 
Temm., Wagl.). The chief differences are that the vent is not 
whitish, but cinereous, and the flanks brownish like the back, not 
light ferruginous. I would consider your bird as the Peruvian 
form of the Brazilian C. aspersus.” 
I have named this bird after Mr. R. J. Balston. 
I may here mention that Crypturus bartletti, Scl. et Salv. (Proc. 
Zool. Soc. 1873, p. 311), was obtained at Santa Cruz on the Hual- 
laga river, E. Peru, not at Santa Cruz de la Sierra, as there stated in 
error. 
5. A Contribution to the Molluscan Fauna of Madagascar. 
By Epear A. Situ. 
[Received April 12, 1882. ] 
(Plates XXI. & XXII.) 
Much still remains to be done before our knowledge of the terres- 
trial and fluviatile Mollusca of Madagascar will attain any thing like 
completeness. With the exception of Achatina fulica, Helix mag- 
nifica, and one or two others, I am not aware that the animals of 
any of the numerous species of shells already described from this 
island have been examined. Of non-operculate land-shells about 
eighty are now known, of operculate species about seventy-five, and 
about fifty forms have been recorded from the lakes and rivers; this 
computation includes the new species about to be described, and a 
few hereafter mentioned for the first time as inhabitants of Mada- 
gascar, which were originally described without localities. One 
minute species, Helix barrakporensis, has not previously been met 
with except in India, where it may have been introduced, as is the 
case with the large Achatina fulica, a most abundant shell in some 
parts of Madagascar and also at the Mauritius. A small South- 
African bivalve shell, Limosina ferruginea, is now cited for the first 
time as an inhabitant of the island; and Spherium madagascariense 
of Tristram is scarcely separable from another African species, S. 
capense of Krauss. Four species belonging to genera not previously 
known from Madagascar are now described ; these are Vitrina mada- 
gascariensis, Cleopatra trabonjiensis, Corbicula madagascariensis, 
and Pisidium johnsoni. 
Part of the collection which is here reported upon was liberally 
presented to the British Museum by Mr. W. Johnson, who has re- 
cently returned to England, and to whom much praise is due for so 
carefully noting the precise localities where he collected the various 
species ; and on this account his name will be found associated with 
